Magnetoresistive memory device assemblies

ABSTRACT

The invention includes a construction comprising an MRAM device between a pair of conductive lines. Each of the conductive lines can generate a magnetic field encompassing at least a portion of the MRAM device. Each of the conductive lines is surrounded on three sides by magnetic material to concentrate the magnetic fields generated by the conductive lines at the MRAM device. The invention also includes a method of forming an assembly containing MRAM devices. A plurality of MRAM devices are formed over a substrate. An electrically conductive material is formed over the MRAM devices, and patterned into a plurality of lines. The lines are in a one-to-one correspondence with the MRAM devices and are spaced from one another. After the conductive material is patterned into lines, a magnetic material is formed to extend over the lines and within spaces between the lines.

TECHNICAL FIELD

[0001] The invention pertains to methods of forming magnetoresistivememory devices, and to methods of forming assemblies comprisingmagnetoresistive memory devices, such as, for example, methods offorming MRAM arrays. The invention also pertains to assembliescomprising magnetoresistive memory devices, such as, for example, MRAMarrays.

BACKGROUND OF THE INVENTION

[0002] Magnetic random access memory (MRAM) devices are showingincreasing promise for utilization as memory storage devices of thefuture. MRAM is a type of digital memory in which digital bits ofinformation comprise alternative states of magnetization of magneticmaterials in memory cells. The magnetic materials can be thinferromagnetic films. Information can be stored and retrieved from thememory devices by inductive sensing to determine a magnetization stateof the devices, or by magnetoresistive sensing of the magnetizationstates of the devices. It is noted that the term “magnetoresistivedevice” can be utilized to characterize a memory device and not theaccess device, and accordingly a magnetoresistive device can be accessedby, for example, either inductive sensing or magnetoresistive sensingmethodologies.

[0003] A significant amount of research is currently being invested inmagnetic digital memories, such as, for example, MRAM's, because suchmemories are seen to have significant potential advantages relative tothe dynamic random access memory (DRAM) components and static randomaccess memory (SRAM) components that are presently in widespread use.For instance, a problem with DRAM is that it relies on electric chargestorage within capacitors. Such capacitors leak electric charge, andmust be refreshed at approximately 64-128 millisecond intervals. Theconstant refreshing of DRAM devices can drain energy from batteriesutilized to power the devices, and can lead to problems with lost datasince information stored in the DRAM devices is lost when power to thedevices is shutdown.

[0004] SRAM devices can avoid some of the problems associated with DRAMdevices, in that SRAM devices do not require constant refreshing.Further, SRAM devices are typically faster than DRAM devices. However,SRAM devices take up more semiconductor real estate than do DRAMdevices. As continuing efforts are made to increase the density ofmemory devices, semiconductor real estate becomes increasingly valuable.Accordingly, SRAM technologies are difficult to incorporate as standardmemory devices in memory arrays.

[0005] MRAM devices have the potential to alleviate the problemsassociated with DRAM devices and SRAM devices. Specifically, MRAMdevices do not require constant refreshing, but instead store data instable magnetic states. Further, the data stored in MRAM devices willremain within the devices even if power to the devices is shutdown orlost. Additionally, MRAM devices can potentially be formed to utilizeless than or equal to the amount of semiconductor real estate associatedwith DRAM devices, and can accordingly potentially be more economical toincorporate into large memory arrays than are SRAM devices.

[0006] Although MRAM devices have potential to be utilized as digitalmemory devices, they are currently not widely utilized. Several problemsassociated with MRAM technologies remain to be addressed. It would bedesirable to develop improved methods for operation of MRAM devices.

[0007]FIG. 1 illustrates a fragment of an exemplary prior artconstruction 10 comprising an MRAM device 12. More specifically,construction 10 comprises a substrate 14 having a conductive line 16formed thereover, and device 12 is formed over the conductive line.

[0008] Substrate 14 can comprise an insulative material, such as, forexample, borophosphosilicate glass (BPSG), silicon dioxide and/orsilicon nitride. Such insulative material can be formed over asemiconductive material, such as, for example, monocrystalline silicon.Further, various integrated circuit devices can be supported by thesemiconductive material. In the construction of FIG. 1, substrate 14 isillustrated generically as a homogeneous mass, but it is to beunderstood from the discussion above that substrate 14 can comprisenumerous materials and layers. In the event that substrate 14 comprisesa semiconductive material, such semiconductive material can be, forexample, monocrystalline silicon lightly-doped with a background p-typedopant. To aid in interpretation of the claims that follow, the terms“semiconductive substrate” and “semiconductor substrate” are defined tomean any construction comprising semiconductive material, including, butnot limited to, bulk semiconductive materials such as a semiconductivewafer (either alone or in assemblies comprising other materialsthereon), and semiconductive material layers (either alone or inassemblies comprising other materials). The term “substrate” refers toany supporting structure, including, but not limited to, thesemiconductive substrates described above.

[0009] Conductive line 16 can comprise, for example, various metals andmetal alloys, such as, for example, copper and/or aluminum.

[0010] The MRAM device 12 formed over line 16 comprises three primarylayers, 18, 20 and 22. Layers 18 and 22 comprise soft magneticmaterials, such as, for example, materials comprising one or more ofnickel, iron, cobalt, iridium, manganese, platinum and ruthenium. Layers18 and 22 can be the same composition as one another, or different fromone another.

[0011] Layer 20 comprises a non-magnetic material. The non-magneticmaterial can be an electrically conductive material (such as copper) inapplications in which the MRAM is to be a giant magnetoresistive (GMR)device, or can be an electrically insulative material (such as, forexample, aluminum oxide (Al₂O₃) or silicon dioxide), in applications inwhich the MRAM device is to be a tunnel magnetoresistive (TMR) device.

[0012] Layers 18 and 22 have magnetic moments associated therewith. Themagnetic moment in layer 18 is illustrated by arrows 19, and themagnetic moment in layer 22 is illustrated by arrows 21. In the shownconstruction, the magnetic moment in layer 22 is anti-parallel to themagnetic moment in layer 18. Such is one of two stable orientations forthe magnetic moment of layer 22 relative to that of 18, with the otherstable orientation being a parallel orientation of the magnetic momentin layer 22 relative to the moment in layer 18. One of layers 18 and 22can have a pinned orientation of the magnetic moment therein, and suchcan be accomplished by providing a hard magnetic layer, or in otherwords a permanent magnet (not shown) adjacent the layer. The layerhaving the pinned magnetic moment can be referred to as a referencelayer.

[0013] In operation, MRAM device 12 can store information as a relativeorientation of the magnetic moment in layer 22 to that in layer 18.Specifically, either the anti-parallel or parallel orientation of themagnetic moments of layers 18 and 22 can be designated as a 0, and theother of the anti-parallel and parallel orientations can be designatedas a 1. Accordingly, a data bit can be stored within device 12 as therelative orientation of magnetic moments in layers 18 and 22.

[0014] A conductive line 24 is shown over layer 22, and such conductiveline extends into and out of the plane of the page. Conductive line 24can comprise, for example, one or more metals and/or metal alloys,including, for example, copper and/or aluminum.

[0015] An insulative material 26 extends over conductive line 16, andalong the sides of bit 12 and conductive line 24. Insulative material 26can comprise, for example, BPSG.

[0016] The construction 10 is an exemplary MRAM construction, and it isto be understood that various modifications can be made to theconstruction 10 for various applications. For instance, one or moreelectrically insulative layers (not shown) can be provided betweendevice 12 and one or both of conductive lines 16 and 24. Also, one ormore magnetic layers (not shown) can be stacked within device 12 inaddition to the shown layers 18 and 22.

[0017] In operation, data is written to MRAM device 12 by passingcurrent along the conductive lines 16 and 24 to change the relativemagnetic orientation of layers 18 and 22 (i.e., to flip the relativeorientation from parallel to anti-parallel, or vice versa). In theory,the relative orientation of layers 18 and 22 can be flipped by passingsufficient current along only one of lines 16 and 24, but in practice itis generally found to be advantageous to utilize both of lines 16 and 24in writing information to device 12. Specifically, some current isinitially passed along one of the lines 16 and 24 to induce a magneticfield in device 12 which starts to flip the relative magneticorientation of layers 18 and 22, and then current is passed along theother of layers 16 and 24 to complete the flip of the relative magneticorientation within device 12.

[0018] The operation of reading information from device 12 can utilizeeither inductive sensing or magnetoresistive sensing to detect therelative magnetic orientation of layers 18 and 22 within the device. Thereading can utilize one or both of lines 16 and 24, and/or can utilize aseparate conductive line (not shown).

[0019] It is advantageous to have lines 16 and 24 be orthogonal to oneanother at the location of device 12 to maximize the complementaryeffect of utilizing both of conductive lines 16 and 24. A device whichutilizes a pair of independently controlled conductive lines for writingto and/or reading from an MRAM device is typically referred to as ahalf-select MRAM construction.

[0020] As discussed above, a single MRAM device can store a single bitof information. Accordingly, in applications in which it is desired toprocess multiple bits of information it is generally desired to utilizea plurality of MRAM devices, with each of the devices independentlystoring bits of information. The devices will typically be arranged inan array, and an exemplary array 50 of MRAM devices is illustrated inFIG. 2. More specifically, FIG. 2 shows a top view of an arraycomprising the construction 10 of FIG. 1. The array comprises a firstset of conductive lines 24, 52, 54 and 56 within the insulative material26; and a second set of conductive lines 16, 58 and 60. The second setof conductive lines is shown as dashed-lines to indicate that the secondset of conductive lines is beneath the insulative material 26 and firstset of conductive lines. Individual MRAM devices (not visible in theview FIG. 2) are at crossings of the first and second sets of conductivelines, with the locations of the devices being designated by labels 10,64, 66, 68, 70, 72, 74, 76, 78, 80, 82, and 84. The various MRAM devicesof the array would typically be fabricated identically to one another,and accordingly can all be identical to the device 12 described in FIG.1.

[0021] Problems can be encountered during operation of an MRAM array ifrelatively large currents are utilized in the first and/or second setsof conductive lines during reading from and/or writing to MRAM devices.Accordingly, it would be desirable to develop methods for reducing theamount of current flow utilized in conductive lines associated with theMRAM array during reading and/or writing operations.

SUMMARY OF THE INVENTION

[0022] In one aspect, the invention encompasses a method of forming amagnetoresistive memory device assembly. A plurality of memory devicesare formed to be supported by a substrate. The memory devices are spacedfrom one another. Each of the memory devices comprises a non-magneticcomposition between a pair of magnetic compositions. An electricallyconductive material is formed over the memory devices. The conductivematerial is patterned into a plurality of lines. The lines are inone-to-one correspondence with the memory devices and are spaced fromone another. After the conductive material is patterned into lines, amagnetic material is formed over the lines. The magnetic materialextends into spaces between the lines.

[0023] In one aspect, the invention encompasses a method of forming anMRAM assembly. A substrate is provided, and the substrate comprises afirst electrically conductive line and a plurality of memory devicesover the first line. Memory devices are spaced from one another by gaps,and the memory devices comprise a non-magnetic composition between apair of magnetic compositions. A mass is formed over the memory devices.Openings are formed to extend through the mass and to the memorydevices. An electrically conductive material is formed within theopenings, and the electrically conductive material within the openingsdefines second electrically conductive lines over the memory devices.The second lines cross the first line at the memory devices. At leastsome of the mass is removed from between the second lines to formopenings. A magnetic material is formed over the second lines. Themagnetic material extends into the openings between the second lines.

[0024] In one aspect, the invention includes an MRAM construction. AnMRAM device is between a pair of conductive lines. Each of theconductive lines can generate a magnetic field encompassing at least aportion of the MRAM device. Each of the conductive lines is surroundedon three sides by magnetic material to concentrate the magnetic fieldsgenerated by the conductive lines at the MRAM device.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Preferred embodiments of the invention are described below withreference to the following accompanying drawings.

[0026]FIG. 1 is a diagrammatic, cross-sectional view of a fragmentillustrating a prior art MRAM construction.

[0027]FIG. 2 is a diagrammatic illustration of a top view of an arraycomprising the MRAM construction of FIG. 1.

[0028]FIG. 3 is a diagrammatic, cross-sectional view of a fragment at apreliminary processing stage of an exemplary method of an aspect of thepresent invention.

[0029]FIG. 4 is a view of the FIG. 3 fragment shown at a processingstage subsequent to that of FIG. 3.

[0030]FIG. 5 is a view of the FIG. 3 fragment shown at a processingstage subsequent to that of FIG. 4.

[0031]FIG. 6 is a view of the FIG. 3 fragment shown at a processingstage subsequent to that of FIG. 5.

[0032]FIG. 7 is a view of the FIG. 3 fragment shown at a processingstage subsequent to that of FIG. 6.

[0033]FIG. 8 is a view of the FIG. 3 fragment shown at a processingstage subsequent to that of FIG. 7.

[0034]FIG. 9 is a view of the FIG. 3 fragment shown at a processingstage subsequent to that of FIG. 6, in accordance with an alternativeaspect of the invention relative to that described in FIGS. 7 and 8.

[0035]FIG. 10 is a view of the FIG. 3 fragment shown at a processingstage subsequent to that of FIG. 6 in accordance with anotheralternative aspect of the invention.

[0036]FIG. 11 is a view of the FIG. 3 fragment shown at a processingstage subsequent to that of FIG. 10.

[0037]FIG. 12 is a view of the FIG. 3 fragment shown at a processingstage subsequent to that of FIG. 5 in accordance with yet anotheralternative aspect of the invention.

[0038]FIG. 13 is a diagrammatic, cross-sectional view of a fragment ofan MRAM assembly at a preliminary processing stage of another aspect ofthe invention.

[0039]FIG. 14 is a view of the FIG. 13 fragment shown at a processingstage subsequent to that of FIG. 13.

[0040]FIG. 15 is a view of the FIG. 13 fragment shown at a processingstage subsequent to that of FIG. 14.

[0041]FIG. 16 is a diagrammatic, top view of an MRAM assemblyillustrating a further aspect of the invention.

[0042]FIG. 17 is a diagrammatic, cross-sectional view along the line17-17 of FIG. 16.

[0043]FIG. 18 is a diagrammatic, cross-sectional view along the line18-18 of FIG. 16.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0044] A first exemplary aspect of the invention is described withreference to FIGS. 3-8. Similar numbering will be used in referring toFIGS. 3-8 as was utilized above in describing prior art FIGS. 1 and 2,where appropriate.

[0045] Referring initially to FIG. 3, a construction 100 is shown incross-sectional view. Construction 100 is illustrated at a preliminaryprocessing step in a method of forming a magnetoresistive memory deviceassembly, such as, for example, an MRAM array.

[0046] Construction 100 comprises a substrate 14 supporting a conductiveline 16. It is noted that in accordance with the definition of“substrate” provided in the background section of this disclosure,portion 14 alone can be considered a substrate, or alternatively,portion 14 and conductive line 16 together can be considered asubstrate.

[0047] MRAM device locations 10, 70, 76 and 82 are defined overconductive line 16, and MRAM devices 12, 102, 104 and 106 are formed inthe locations. The MRAM devices can be considered memory devices. Eachof the memory devices comprises a non-magnetic composition (or mass) 20between a pair of magnetic compositions (or masses) 18 and 22. Thememory devices comprise upper surfaces 107, and sidewall surfaces 108.

[0048] Memory devices 12, 102, 104 and 106 are separated by spaces (orgaps) 110, 112 and 114. Accordingly, the memory devices are spaced fromone another.

[0049] A mass 116 is formed over conductive line 16, and openings 118,120, 122 and 124 extend through the mass to upper surfaces 107 of memorydevices 12, 102, 104 and 106. Mass 116 can comprise, for example, anelectrically insulative material, such as one or more ofborophosphosilicate glass (BPSG), silicon dioxide and silicon nitride.In exemplary aspects of the invention, mass 116 can initially formed toextend across the memory devices, and subsequently openings 118, 120,122 and 124 can be formed within the mass. The openings can be formedby, for example, initially providing a patterned mask (not shown) overmass 116, and then extending a pattern of the mask into mass 116 to formthe openings. The patterned mask can comprise, for example, photoresist,and a pattern within the mask can be formed by, for example,photolithographic processing. Openings 118, 120, 122 and 124 arecomplimentary to lines (discussed below) which are ultimately formedwithin the openings.

[0050] Referring to FIG. 4, an electrically conductive material (ormass) 130 is provided over mass 116 and within openings 118, 120, 122and 124 (FIG. 3). Conductive material 130 can comprise, for example,various metals or metal alloys, and in particular aspects can compriseone or both of copper and aluminum. Conductive material 130 is formedover memory devices 12, 102, 104 and 106, and in the shown embodimentphysically contacts upper surfaces 107 of the devices. It is to beunderstood, however, that the invention can encompass other aspects (notshown) wherein an insulative or other material is provided overuppermost surfaces 107 prior to forming conductive material 130.

[0051] Mass 116 comprises an uppermost surface 117, and in the shownaspect of the invention, conductive material 130 is formed overuppermost surface 117.

[0052] Referring to FIG. 5, construction 100 is subjected toplanarization (such as, for example, chemical-mechanical polishing) toform a planarized upper surface 132, and to remove material 130 fromover uppermost surface 117 of mass 116. Planarized surface 132 is showncoextensive with uppermost surface 117 of mass 116. It is to beunderstood, however, that the planarization can remove portions of mass116, in addition to removing conductive material 130 from over mass 116.Accordingly, the uppermost surface 117 of FIG. 5 can be at a lowerelevational level than the uppermost surface 117 of FIG. 4. The material130 remaining in the construction 100 of FIG. 5 forms lines 24, 52, 54and 56. The lines are in a one-to-one correspondence with memory devices12, 102, 104 and 106. Further, the lines are spaced from one another bygaps coextensive with the gaps 110, 112 and 114 between the memorydevices. The lines have top surfaces 141, and side surfaces 143 (withthe top and side surfaces being labeled for only one of the lines).

[0053] Referring to FIG. 6, some of mass 116 is removed from within gaps110, 112 and 114, and such reduces an elevational level of the masswithin the gaps. In the shown aspect of the invention, a portion of theinsulative mass 116 has been removed from between the conductive lines,but the insulative mass has not been removed from between the memorydevices. The portion of mass 116 remaining within gaps 110, 112 and 114is thicker than an elevational thickness of memory devices 12, 102, 104and 106. Accordingly, the remaining portions of mass 116 entirely coversidewalls 108 (FIG. 3) of the memory devices. Although portions of mass116 remain within gaps 110, 112 and 114 in the shown aspect of theinvention, it is to be understood that an entirety of mass 116 can beremoved from within the gaps in other aspects of the invention(discussed below). The removal of some or all of mass 116 can beaccomplished with either a dry or wet etch.

[0054] The reduction in thickness of mass 116 exposes sidewalls 143 oflines 24, 52, 54 and 56.

[0055] Referring to FIG. 7, a dielectric material 150 is formed overconductive lines 24, 52, 54 and 56, as well as across upper surfaces ofmass 116 within gaps 110, 112 and 114. Dielectric material 150 is formedas a continuous expanse extending along sidewall surfaces 143 and topsurfaces 141 of conductive lines 24, 52, 54 and 56, as well as over thesubstrate 14 within the spaces 110, 112 and 114 between the conductivelines. The dielectric material can comprise, for example, one or more ofsilicon dioxide, silicon nitride and aluminum oxide; and can be formedto a thickness of, for example, from about 100 Å to about 200 Å. Thedielectric material can be formed by, for example, chemical vapordeposition.

[0056] A magnetic material 152 is formed over dielectric material 150.The magnetic material extends over lines 24, 52, 54 and 56, and into thespaces 110, 112 and 114 between the lines. In the shown application, themagnetic material is, like the dielectric material, formed to be acontinuous expanse extending along sidewall surfaces and top surfaces oflines, as well as over the substrate within spaces between the lines.The magnetic material can comprise a thickness of, for example, fromabout 50 Å to about 100 Å, and can comprise various ferromagneticmaterials. In particular aspects, the magnetic material comprises one ormore of iron, nickel and cobalt. The magnetic material can be formed byany of various deposition processes, including, for example, physicalvapor deposition. An exemplary physical vapor deposition process issputter deposition.

[0057] The magnetic material 152 can, in particular aspects, beconsidered a cladding around conductive lines 24, 52, 54 and 56. Thecladding can concentrate magnetic fields formed by current passingthrough the conductive lines, and specifically can concentrate themagnetic fields within memory devices 12, 102, 104 and 106. Referring toline 24 and memory device 12 as an example, the magnetic field (ormoment) induced at device 12 by current flow through line 24 can beenhanced by the cladding of magnetic material 152 relative to themagnetic field that would result from the same amount of current in theabsence of the cladding. For instance, if it is desired to obtain amagnetic field of about 50 oersteds at memory device 12, a current offrom about 2 milliamps to about 3 milliamps would typically be flowedthrough the conductive line 24 to induce the desired magnetic field.However, the presence of magnetic material 152 can enable a current flowof only 1 milliamp to be sufficient to induce the desired 50 oersteds atmemory device 12. Accordingly, methodology of the present invention canenable a lower amount of current to be flowed through conductive linesproximate MRAM devices, while still producing desired magnetic fields atthe devices. Such reduction in current flow can alleviate problemsassociated with prior art MRAM arrays.

[0058] Referring to FIG. 8, an insulative mass 160 is provided overmagnetic material 152. Mass 160 comprises an upper surface 161 which canbe planarized. Subsequently, additional devices (not shown) can beformed over such upper surface.

[0059] The processing described above with reference to FIGS. 3-8 is butone example of processing that can be utilized to form a magneticmaterial around lines associated with an MRAM array. FIG. 9 illustratesanother exemplary process. Specifically, FIG. 9 illustrates theconstruction 100 at a processing step subsequent to FIG. 7, andillustrates that segments of magnetic material 152 and dielectricmaterial 150 have been removed from within the gaps 110, 112 and 114between lines 24, 52, 54 and 56. However, the dielectric material 150and conductive material 152 remain along sidewall and top surfaces ofthe conductive lines 24, 52, 54 and 56. Accordingly, the magneticmaterial 152 remains around peripheries of the conductive lines in anorientation where it can direct magnetic fields generated by currentpassing through the conductive lines downwardly toward memory devicesbeneath the conductive lines. In subsequent processing, (not shown) aninsulative material (such as the material 160 of FIG. 8) can be formedover the conductive lines and across the gaps between the conductivelines.

[0060] Another aspect of the invention is described with reference toFIGS. 10 and 11. In referring to FIGS. 10 and 11, similar numbering willbe used as was utilized above in describing FIGS. 3-8, whereappropriate.

[0061] Referring to FIG. 10, a construction 200 is illustrated at aprocessing step subsequent to FIG. 6. Magnetic material 152 is formedover lines 24, 52, 54 and 56. The magnetic material extends alongsidewall and top surfaces of the lines, and further extends across gaps110, 112 and 114 between the lines. The construction 200 of FIG. 10 isshown at a similar processing step to the construction 100 of FIG. 7,but differs from the construction 100 of FIG. 7 in that the dielectricmaterial 150 (FIG. 7) is not provided in the construction 200.

[0062] A patterned mask 202 is formed over portions of magnetic material152 associated with conductive lines 24, 52, 54 and 56 while leavingportions of magnetic material 152 within gaps 110, 112 and 114 exposed.Patterned mask 202 can comprise, for example, photoresist, and can bepatterned utilizing photolithographic processing.

[0063] Referring to FIG. 11, exposed portions of magnetic material 152are removed from within gaps 110, 112 and 114, and subsequently mask 202(FIG. 10) is removed. The magnetic material 152 remaining is alongsidewalls 143 and top surfaces 141 of lines 24, 52, 54 and 56. Further,magnetic material 152 is physically against such sidewall and topsurfaces of the lines. It is preferred that magnetic material 152 doesnot contact either of the magnetic compositions 18 and 22 of memorydevices 12, 102, 104 and 106. The insulative material 116 previouslyformed within gaps 110, 112 and 114 prevents magnetic material 152 fromphysically contacting the magnetic compositions of the memory devices.

[0064] The removal of exposed portions of magnetic material 152 to formthe shown pattern in FIG. 11 can be considered as transferring a patternfrom mask 202 to the underlying conductive material 152.

[0065] Another aspect of the invention is described with reference toFIG. 12. In describing FIG. 12 similar numbering will be used as wasutilized above in describing FIGS. 3-8, where appropriate. FIG. 12illustrates a construction 300 shown at a processing step subsequent tothat of FIG. 5. Specifically, the insulative mass 116 (FIG. 5) has beenentirely removed from within gaps 110, 112 and 114, and subsequentlydielectric material 150 and magnetic material 152 are formed. Thedielectric material 150 prevents magnetic material 152 from physicallycontacting magnetic compositions 18 and 22 of memory devices 12, 102,104 and 106. In subsequent processing (not shown) one or both ofmagnetic material 152 and dielectric material 150 can be removed fromwithin gaps 110, 112 and 114. Alternatively, materials 150 and 152 canbe left within gaps 110, 112 and 114 in completed devices formed inaccordance with the methodology of FIG. 12.

[0066] FIGS. 13-15 illustrate another aspect of the invention. Inreferring to FIGS. 13-15 similar numbering will be used as was utilizedabove in describing the embodiment of FIGS. 3-8, where appropriate. FIG.13 illustrates a construction 400 comprising substrate 14, conductiveline 16, and memory devices 12, 102, 104 and 106. Electricallyconductive material 130 is formed over memory devices 12, 102, 104 and106, as well as within gaps 110, 112 and 114 between the devices.

[0067] Referring to FIG. 14, an upper surface of material 130 isplanarized to form a planar upper surface 401. The planarization can beaccomplished by, for example, chemical-mechanical polishing A patternedmask 402 is formed over planar surface 401. Mask 402 can comprise, forexample, photoresist and can be patterned utilizing photolithographicprocessing. Mask 402 comprises portions over memory devices 12, 102, 104and 106. Gaps 404 are between the portions of mask 402, and conductivematerial 130 is exposed within such gaps. Gaps 404 are over the spaces110, 112 and 114 between memory devices 12, 102, 104 and 106.

[0068] Referring to FIG. 15, a pattern is transferred from mask 402(FIG. 14) to conductive material 130, and subsequently mask 402 isremoved. The transferring of the pattern from mask 402 to material 130results in portions of conductive material exposed within openings 404(FIG. 14) being removed. The conductive material 130 remaining at theprocessing stage of FIG. 15 is in the form of lines 24, 52, 54 and 56.In subsequent processing (not shown) an insulative material can beprovided between memory devices 12, 102, 104 and 106 to form a layeranalogous to the layer 116 of FIG. 6. Subsequently, any of theprocessing described above with references to FIGS. 7-11 can beconducted to form the various constructions showing FIGS. 7-11.Alternatively, the dielectric material 150 and magnetic material 152(discussed above) can be provided over lines 24, 52, 54 and 56, as wellas within spaces between the lines to generate a construction analogousto that shown in FIG. 12.

[0069] The conductive lines 24, 52, 54 and 56 discussed above withreferences to various of FIGS. 3-15 can have a same type of relativeconfiguration as that shown in the array of FIG. 2, and further theconductive line 16 of FIGS. 3-15 can have the same type of configurationas that shown in the array of FIG. 2. Accordingly, lines 24, 52, 54 and56 can be considered to cross line 16 at locations corresponding tomemory devices 12, 102, 104 and 106. Additionally, lines 24, 52, 54 and56 can extend along directions that are primarily parallel to oneanother, and further can extend along directions which are substantiallyorthogonal to the direction along which conductive line 16 extends. Theterm “substantially orthogonal” is utilized to indicate that lines 24,52, 54 and 56 can be orthogonal relative to line 16 within tolerances offabrication and measurement, which can be different than “orthogonal” isunderstood in an absolute mathematical sense.

[0070] The magnetic material 152 (see, for example, FIGS. 8, 9, 11 and12) can be considered to be a three-sided magnetic flux concentratorconductor which concentrates a magnetic field within an adjacent memorydevice. Various methods have been developed for providing magnetic fluxconcentrators around a bottom line associated with magnetoresistivedevices (see, for example, U.S. Pat. No. 5,956,267). The presentinvention provides a method for forming flux concentrators around thetop lines associated with an MRAM array. Methodology of the presentinvention can be utilized in combination with the prior art methodologyto form MRAM arrays in which flux concentrators are provided around bothbottom and top lines. It is considered that if flux concentrators areprovided on three sides of bottom lines, and also on three sides of toplines, the magnetic field induced by current flow through the top andbottom lines can be increased by at least two times relative to acurrent flow which would exist in the absence of the flux concentrators,and possibly by four times, or even more than four times, relative tothe magnetic field that would be induced in the absence of the fluxconcentrators.

[0071] FIGS. 16-18 illustrate an aspect of the invention in which fluxconcentrators are provided around opposing lines (such as bottom and toplines) associated with a half-select MRAM device. Similar numbering willbe utilized in referring to FIGS. 16-18 as was used in describing theconstructions of FIGS. 3-15, where appropriate.

[0072] Referring to FIG. 16, a construction 500 is illustrated in topview. Construction 500 comprises a substrate 502 and a pair of lineconstructions 504 and 506 supported by the substrate. The lines cross atan MRAM device (not visible in the view of FIG. 16).

[0073] Referring to the cross-sectional views of FIGS. 17 and 18, theMRAM device between the line constructions is visible as a device 12.Device 12 comprises a pair of magnetic compositions (18 and 22)separated by a non-magnetic composition (20). Device 12 can be part ofan MRAM array.

[0074] An electrically insulative mass 116 is along sidewalls of device12, and line construction 504 is over the mass 116. Line construction504 comprises a conductive line 24 having an outer periphery 510. Line24 is surrounded on three sides by dielectric material 150 and magneticmaterial 152. In particular aspects, magnetic material 152 can beconsidered to surround a portion, and only a portion, of outer periphery510 of line 24. Although magnetic material 152 is shown extendingentirely across the sides of line 24, it is to be understood that themagnetic material can, in alternative aspects of the invention, extendonly partially along the sides of line 24. Also, although line 24 isshown having a rectangular cross-sectional shape across an end of theline (see FIG. 18), and to accordingly have four sides to outerperiphery 510, it is to be understood that line 24 can have othershapes.

[0075] Device 12 is over line construction 506. Line construction 506comprises a conductive line 16 having an outer periphery 512. Line 16 issurrounded on three sides by a magnetic material 508. Line construction506 can be formed by, for example, methodology described in U.S. Pat.No. 5,956,267. In particular aspects, magnetic material 508 can beconsidered to surround a portion, and only a portion, of outer periphery512 of line 16. Although magnetic material 508 is shown extendingentirely across the sides of line 16, it is to be understood that themagnetic material can, in alternative aspects of the invention, extendonly partially along the sides of line 16. Also, although line 16 isshown having a rectangular cross-sectional shape across an end of theline (see FIG. 17), and to accordingly have four sides to outerperiphery 512, it is to be understood that line 16 can have othershapes.

[0076] Magnetic material 508 can be identical in composition to magneticmaterial 152, or different. In particular aspects, both of magneticmaterials 508 and 152 will comprise one or more of Fe, Ni and Co.

[0077] In compliance with the statute, the invention has been describedin language more or less specific as to structural and methodicalfeatures. It is to be understood, however, that the invention is notlimited to the specific features shown and described, since the meansherein disclosed comprise preferred forms of putting the invention intoeffect. The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

1. A method of forming a magnetoresistive memory device assembly,comprising: forming a plurality of memory devices supported by asubstrate and spaced from one another, each of the memory devicescomprising a non-magnetic composition between a pair of magneticcompositions; forming an electrically conductive material over thememory devices; patterning the conductive material into a plurality oflines; the lines being in one-to-one correspondence with the memorydevices and being spaced from one another; and after patterning theconductive material into lines, forming a magnetic material over thelines and extending into spaces between the lines.
 2. The method ofclaim 1 wherein the conductive material physically contacts one of themagnetic compositions of the memory devices.
 3. The method of claim 1wherein the lines comprise sidewall surfaces and top surfaces; andwherein the magnetic material is formed to be a continuous expanseextending along the sidewall surfaces and top surfaces of the lines, aswell as over the substrate within spaces between the lines.
 4. Themethod of claim 2 further comprising removing segments of the magneticmaterial from within the spaces between the lines while leaving themagnetic material along the sidewall and top surfaces of the lines. 5.The method of claim 1 further comprising forming a dielectric materialover the lines, and forming the magnetic material over the dielectricmaterial.
 6. The method of claim 5 wherein the dielectric materialcomprises one or more of silicon dioxide, silicon nitride and aluminumoxide.
 7. The method of claim 5 wherein: the lines comprise sidewallsurfaces and top surfaces; the dielectric material is formed to be acontinuous expanse extending along the sidewall surfaces and topsurfaces of the lines, as well as over the substrate within spacesbetween the lines; the magnetic material is formed to be a continuousexpanse extending along the sidewall surfaces and top surfaces of thelines, as well as over the substrate within spaces between the lines. 8.The method of claim 7 further comprising removing segments of themagnetic material from within the spaces between the lines while leavingthe magnetic material along the sidewall and top surfaces of the lines.9. The method of claim 7 further comprising removing segments of themagnetic material and dielectric material from within the spaces betweenthe lines while leaving the magnetic material and dielectric materialalong the sidewall and top surfaces of the lines.
 10. The method ofclaim 1 further comprising: forming an insulative material in the spacesbetween the memory devices; and forming the magnetic material over theinsulative material, the insulative material preventing the magneticmaterial from physically contacting the magnetic compositions of thememory devices.
 11. The method of claim 1 wherein the conductivematerial is formed as an expanse extending across the memory devices;and wherein the patterning the conductive material into lines comprisesforming a patterned mask over the conductive material and etching theconductive material to transfer a pattern from the mask to theconductive material.
 12. The method of claim 1 further comprising:forming a mass over the memory devices: forming openings through themass and to the memory devices, the openings being complementary to thelines that are to be formed from the conductive material; and whereinthe forming the conductive material comprises forming the conductivematerial within the openings extending through mass; the conductivematerial being patterned into the lines as it is formed within theopenings.
 13. The method of claim 12 wherein the conductive material isformed to extend above an upper surface of the mass, and furthercomprising utilizing chemical-mechanical polishing to remove theconductive material from above said upper surface.
 14. The method ofclaim 1 wherein the magnetic material comprises a thickness of fromabout 50 Å to about 100 Å.
 15. The method of claim 1 wherein themagnetic material comprises one or more of iron, nickel and cobalt. 16.A method of forming a magnetoresistive memory device assembly,comprising: forming a plurality of memory devices supported by asubstrate, each of the memory devices comprising a non-magneticcomposition between a pair of magnetic compositions; forming anelectrically insulative material over the memory devices; formingopenings extending through the insulative material to the memorydevices; forming an electrically conductive material within the openingsto form lines over the memory devices; removing at least some of theinsulative material from between the lines to form openings between thelines, but not removing the insulative material from between the memorydevices; and forming a magnetic material over the lines and extendinginto the openings between the lines.
 17. The method of claim 16 whereinthe conductive material is formed to extend above an upper surface ofthe insulative material, and further comprising utilizingchemical-mechanical polishing to remove the conductive material fromabove said upper surface.
 18. The method of claim 16 wherein the linescomprise sidewall surfaces and top surfaces; and wherein the magneticmaterial is formed to be a continuous expanse extending along thesidewall surfaces and top surfaces of the lines, as well as over thesubstrate within spaces between the lines.
 19. The method of claim 18further comprising removing segments of the magnetic material fromwithin the spaces between the lines while leaving the magnetic materialalong the sidewall and top surfaces of the lines.
 20. The method ofclaim 16 further comprising forming a dielectric material over thelines, and forming the magnetic material over the dielectric material.21. The method of claim 20 wherein the dielectric material comprises oneor more of silicon dioxide, silicon nitride and aluminum oxide.
 22. Themethod of claim 20 wherein the dielectric material comprises a thicknessof from about 100 Å to about 200 Å.
 23. The method of claim 20 wherein:the lines comprise sidewall surfaces and top surfaces; the dielectricmaterial is formed to be a continuous expanse extending along thesidewall surfaces and top surfaces of the lines, as well as over thesubstrate within spaces between the lines; the magnetic material isformed to be a continuous expanse extending along the sidewall surfacesand top surfaces of the lines, as well as over the substrate withinspaces between the lines.
 24. The method of claim 23 further comprisingremoving segments of the magnetic material from within the spacesbetween the lines while leaving the magnetic material along the sidewalland top surfaces of the lines.
 25. The method of claim 23 furthercomprising removing segments of the magnetic and dielectric materialsfrom within the spaces between the lines while leaving the magnetic anddielectric materials along the sidewall and top surfaces of the lines.26. The method of claim 16 wherein the insulative material comprises oneor more of borophosphosilicate glass, silicon dioxide and siliconnitride.
 27. The method of claim 16 wherein the magnetic materialcomprises one or more of iron, nickel and cobalt.
 28. A method offorming a magnetoresistive memory device assembly, comprising: providinga substrate comprising a first electrically conductive line and aplurality of memory devices over the first line, the memory devicesbeing spaced from one another; individual memory devices of theplurality comprising a non-magnetic composition between a pair ofmagnetic compositions; forming a mass over the memory devices; formingopenings extending through the mass to the memory devices; forming anelectrically conductive material within the openings to form secondelectrically conductive lines over the memory devices; the second linescrossing the first line at the memory devices; removing at least some ofthe mass from between the second lines to form openings between thesecond lines; and forming a magnetic material over the second lines andextending into the openings between the second lines.
 29. The method ofclaim 28 wherein the conductive material is formed to extend above anupper surface of the mass, and further comprising utilizingchemical-mechanical polishing to remove the conductive material fromabove said upper surface.
 30. The method of claim 28 wherein the linescomprise sidewall surfaces and top surfaces; and wherein the magneticmaterial is formed to be a continuous expanse extending along thesidewall surfaces and top surfaces of the lines, as well as over thesubstrate within spaces between the lines.
 31. The method of claim 30further comprising removing segments of the magnetic material fromwithin the spaces between the lines while leaving the magnetic materialalong the sidewall and top surfaces of the lines.
 32. The method ofclaim 28 further comprising forming a dielectric material over thelines, and forming the magnetic material over the dielectric material.33. The method of claim 28 wherein the dielectric material comprises oneor more of silicon dioxide, silicon nitride and aluminum oxide.
 34. Themethod of claim 28 wherein: the lines comprise sidewall surfaces and topsurfaces; the dielectric material is formed to be a continuous expanseextending along the sidewall surfaces and top surfaces of the lines, aswell as over the substrate within spaces between the lines; the magneticmaterial is formed to be a continuous expanse extending along thesidewall surfaces and top surfaces of the lines, as well as over thesubstrate within spaces between the lines.
 35. The method of claim 34further comprising removing segments of the magnetic material fromwithin the spaces between the lines while leaving the magnetic materialalong the sidewall and top surfaces of the lines.
 36. The method ofclaim 34 further comprising removing segments of the magnetic anddielectric materials from within the spaces between the lines whileleaving the magnetic and dielectric materials along the sidewall and topsurfaces of the lines.
 37. The method of claim 28 wherein the magneticmaterial comprises one or more of iron, nickel and cobalt.
 38. Themethod of claim 28 wherein the first line extends primarily along afirst direction and the second lines extend primarily along a seconddirection; and wherein the second direction is substantially orthogonalto the first direction.
 39. A method of forming a magnetoresistivememory device assembly, comprising: forming a plurality of memorydevices supported by a substrate, individual memory devices of theplurality comprising a non-magnetic composition between a pair ofmagnetic compositions; the memory devices being spaced from one another;forming an electrically conductive material extending over the memorydevices and across spaces between the memory devices; forming apatterned mask over the conductive material; the patterned mask coveringsome portions of the conductive material and leaving other portionsexposed; removing the exposed portions of the conductive material; theconductive material remaining after removal of the exposed portionsbeing a plurality of lines; the lines being in one-to-one correspondencewith the memory devices and being spaced from one another; the lineshaving top surfaces and side surfaces; forming a dielectric materialextending across the top and side surfaces of the lines; the dielectricmaterial also extending across spaces between the lines; and forming amagnetic material over the dielectric material; the magnetic materialextending across the top and side surfaces of the lines; the magneticmaterial also extending across spaces between the lines.
 40. The methodof claim 39 wherein the substrate comprises a first line beneath thememory devices; wherein the lines formed from the conductive materialare second lines; wherein the first line extends primarily along a firstdirection under the memory devices; wherein regions of the second linesover the memory devices extend primarily in a direction orthogonal tothe first direction; and wherein the first lines, memory devices andsecond lines are together incorporated into half-select memory devices.41. The method of claim 40 wherein the first line physically contactsone of the magnetic compositions of said pair of magnetic compositionsof the memory devices.
 42. The method of claim 40 wherein the secondlines physically contact one of the magnetic compositions of said pairof magnetic compositions of the memory devices.
 43. The method of claim40 wherein the first line physically contacts one of the magneticcompositions of said pair of magnetic compositions of the memorydevices; and wherein the second lines physically contact the other ofthe magnetic compositions of said pair of magnetic compositions of thememory devices.
 44. The method of claim 39 wherein the patterned maskcomprises photo resist.
 45. The method of claim 39 wherein the magneticcompositions of said pair of magnetic compositions are identical to oneanother.
 46. The method of claim 39 wherein the magnetic compositions ofsaid pair of magnetic compositions are different from one another. 47.The method of claim 39 wherein the dielectric material comprises one ormore of silicon dioxide, silicon nitride and aluminum oxide.
 48. Themethod of claim 39 wherein the dielectric material comprises a thicknessof from about 100 Å to about 200 Å.
 49. The method of claim 39 whereinthe memory devices comprise side surfaces, and wherein the dielectricmaterial physically contacts at least one of the magnetic compositionsof said pair of magnetic compositions along the side surfaces of thememory devices.
 50. The method of claim 39 wherein the memory devicescomprise side surfaces, and wherein the dielectric material physicallycontacts the pair of magnetic compositions and the non-magneticcomposition along the side surfaces of the memory devices.
 51. Themethod of claim 39 further comprising removing segments of the magneticmaterial from within the spaces between the lines while leaving themagnetic material along the sidewall and top surfaces of the lines. 52.The method of claim 39 further comprising removing segments of thedielectric material and magnetic material from within the spaces betweenthe lines while leaving the dielectric material and magnetic materialalong the sidewall and top surfaces of the lines.
 53. A magnetoresistivememory device assembly, comprising: a memory device supported by asubstrate, the memory device including a non-magnetic compositionbetween a pair of magnetic compositions; a first electrically conductiveline on one side of the memory device; the first electrically conductiveline being configured to generate a magnetic field overlapping at leasta portion of the memory device when current is passed through the firstconductive line; a first magnetic material around a portion of an outerperiphery of the first conductive line and configured to concentrate themagnetic field overlapping at least a portion of the memory device whencurrent passes through the first conductive line; a second electricallyconductive line on a side of the memory device in opposing relation tosaid one side; the second electrically conductive line being configuredto generate a magnetic field overlapping at least a portion of thememory device when current is passed through the second conductive line;and a second magnetic material around a portion of an outer periphery ofthe second conductive line and configured to concentrate the magneticfield overlapping at least a portion of the memory device when currentpasses through the second conductive line.
 54. The device of claim 53wherein the first line comprises a rectangular cross-sectional shapewith the outer periphery of the first line extending along four sides ofthe rectangular cross-sectional shape; and wherein the first magneticmaterial extends entirely along three of the four sides.
 55. The deviceof claim 53 wherein the first line comprises a rectangularcross-sectional shape with the outer periphery of the first lineextending along four sides of the rectangular cross-sectional shape; andwherein the first magnetic material extends entirely along one of thefour sides, and extends only partially along two other of the foursides.
 56. The device of claim 53 wherein the second line comprises arectangular cross-sectional shape with the outer periphery of the secondline extending along four sides of the rectangular cross-sectionalshape; and wherein the second magnetic material extends entirely alongthree of the four sides.
 57. The device of claim 53 wherein: the firstline comprises a rectangular cross-sectional shape with the outerperiphery of the first line extending along four sides of therectangular cross-sectional shape of the first line; the first magneticmaterial extending entirely along three of the four sides of therectangular cross-sectional shape of the first line; the second linecomprises a rectangular cross-sectional shape with the outer peripheryof the second line extending along four sides of the rectangularcross-sectional shape; the second magnetic material extending entirelyalong three of the four sides of the rectangular cross-sectional shapeof the second line.
 58. The device of claim 53 wherein the first andsecond magnetic materials both comprise one or more of Fe, Ni and Co.59. The device of claim 53 wherein the first and second magneticmaterials are identical in composition relative to one another.
 60. Thedevice of claim 53 wherein the first and second magnetic materials aredifferent in composition relative to one another.